Energy absorbing ball

ABSTRACT

An energy absorbing ball has a spherical resilient shell having a smooth inner surface and a smooth outer surface. A fill material is introduced into the shell via a fill opening in the shell. The fill material includes a liquid and a solid particulate having a density greater than the liquid, and with the fill material substantially entirely filling the shell. A plug in the fill opening seals the fill material within the shell, optionally with a recess over the plug. The smooth inside and outside surfaces of the she are spherical and free of any projections or obstructions.

BACKGROUND OF THE INVENTION

The invention relates to an energy absorbing ball, and more specificallyto an energy absorbing weighted ball for practicing ball throwing,catching and hitting.

Many energy absorbing balls have been proposed with varying uses, suchas lawn bowling, street hockey, indoor games, baseball training, etc.Generally these types of energy absorbing balls have an impact resistantresilient rubber or plastic shell containing a filler material that mayinclude solid particles, bulk weights, liquids and/or gases. The filermaterial is typically provided to absorb and distribute impact forces onthe ball, or to increase rolling and rebounding resistance. Althoughseveral of these designs have achieved varying degrees of success,engineering challenges remain to providing a still further improvedenergy absorbing ball.

SUMMARY OF THE INVENTION

An energy absorbing ball has a spherical resilient shell having a smoothinner surface and a smooth outer surface. A fill material s introducedinto the shell via a fill opening in the shell. The fill materialincludes a liquid and a solid particulate having a density greater thanthe liquid, and with the fill material substantially entirely filing theshell. A plug in the fill opening seals the fill material within theshell, optionally with a recess over the plug. The smooth inside andoutside surfaces of the shell are spherical and free of any projectionsor obstructions.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a weighted ball.

FIG. 2 is a section view of the ball shown in FIG. 1.

FIG. 3 is an exploded perspective view of the ball shown in FIG. 1.

DETAILED DESCRIPTION OF THE DRAWINGS

As shown in FIGS. 1-3, a weighted energy absorbing ball 10 has aresilient plastic or rubber spherical shell 10 containing a fillmaterial 16. The shell has a smooth inside surface 14 and a smoothoutside surface 12, and a wall thickness generally of about 2-5millimeters. The ball diameter is 5-15 or 6-8 cm. The shell 10 may beformed by joining to molded hemispherical half spheres together, Thesmooth inside surface 12 is free of any projections or obstructions,other than manufacturing artifacts.

A fill opening 18 may be molded into or otherwise provided in the ball,to allow for filling the ball with the fill material. After the ball isfilled, a plug 20 may be permanently installed into the fill opening 18using known techniques, such as pressing the plug into the fill openingand using bonding or adhesive materials. The outside surface 12 of theball 10 is smooth and continuous, except at the fill opening 18, wherethe top of the plug 20 may not be flush with the surrounding sphericalsurface, and potentially with a slight annular gap (e.g., 0.1 mm)between the plug 20 and the surrounding spherical surface, leaving arecess 22 over the fill opening. As the plug 20 completely andpermanently seals the shell, no additional sealing materials or devicesare needed.

The fill material is a mixture of a liquid, such a light oil, and aparticulate such as iron sand. In some embodiments, the oil may bereplaced with salt water or an anti-freeze liquid, to prevent the fillmaterial from freezing in cold conditions. The liquid and theparticulate are selected so that they do not react with each other, andso that the particulate does not dissolve or clump up. The particulatemay alternatively comprise iron filings, sand or other particulate suchas metal or glass beads.

The particulate is heavier than the liquid. With the ball at rest, theparticulate sinks to the bottom, with the liquid displaced above theparticulate. The total weight of the ball including the shell and thefill material generally ranges from about 275 to 575 grams, moretypically about 375 to 475 grams. The particulate forms the bulk of thefill material, generally making up 50 or 60 to 90 or 95% of the weightof the fill material, with the balance being the liquid. The ratio ofparticulate to liquid will vary depending on the liquid and particulateselected, the size and weight of the ball, and other factors.

The fill material substantially entirely fills the shell 10, with nosignificant air space remaining in the shell after it is filled. Thefill material, which is largely incompressible, helps the ball tomaintain its spherical shape when subjected to impact forces, incontrast to balls containing air, which is compressible.Correspondingly, the ball 10 does not require an air fill port and maytherefore be permanently sealed after manufacture at the factory. Theshell may contain positive pressure if the fill material is injected andsealed under positive pressure conditions.

In use, as the ball 10 impacts against a surface such as a wall, a bator the ground, the impact force is distributed within the ball via thefill material. As the density of the particulate is greater than theliquid, the particulate tends to at least initially be at the bottom ofthe ball 10. The center of gravity of the ball 10 is then below theequator. As a result, the ball may roll with an eccentric movement,although rolling is minimal due to the damping effect of the fillmaterial. Correspondingly, if the ball is agitated to temporarily moreevenly distribute the particulate within the liquid, the ball will rollfurther with less eccentric movement.

As the shell is resilient, the ball 10 is deformable using nominal handforce. The ball 10 may also be used as a hand-held exercise ball. Asused here, substantially no air or gas means less than 1, 2, 3, 4 or 5%of the volume of the ball, and substantially filling the ball meansfilling 95% or more of the volume of the ball,

Thus, a novel ball has been shown and described. Various changes andsubstitutions may of course be made without departing from the spiritand scope of the invention. The invention, therefore, should not belimited except by the following claims and their equivalents.

1. An energy absorbing ball, comprising: a spherical resilient shellhaving a smooth inner surface and a smooth outer surface; a hollow fillstem projecting radially inward from the smooth inner surface, thehollow fill stem having a fill opening extending from the smooth outersurface to an interior cavity of the spherical resilient shell; a fillmaterial within the interior cavity, the fill material comprising aliquid and a solid particulate having a density greater than the liquid,and with the fill material substantially entirely filling the shell; anda plug in the hollow fill stem and obstructing the fill opening to sealthe fill material within the interior cavity, wherein the plug isdisposed below the smooth outer surface such that an empty recess isformed below the smooth outer surface to a top portion of the plug. 2.The ball of claim 1 with the fill material sealed within the shell onlyby the plug.
 3. The ball of claim 1 with the ball containingsubstantially no air or gas.
 4. The ball of claim 1 with the shellhaving a uniform wall thickness generally of about 2-4 millimeters. 5.The ball of claim 4 with the shell having an outer diameter of 6-8 cm.6. The ball of claim 5 with the smooth inner surface of the shell freeof any projections or obstructions other than the hollow fill stem. 7.The ball of claim 6 with the liquid comprising oil and the particulatecomprising iron sand.
 8. The ball of claim 6 with the particulatecomprising metal filings, sand, metal beads or glass beads.
 9. The ballof claim 8 with the ball weighing 375 to 475 grams.
 10. The ball ofclaim 1, wherein: the spherical resilient shell is formed of rubber orplastic, the shell having a uniform wall thickness of 2-4 millimetersand an outer diameter of 6-8 cm; the hollow fill stem is molded into theshell; and the liquid of the fill material is oil and the particulate ofthe fill material has a density greater than the oil.
 11. The ball ofclaim 10 with the smooth inner surface of the shell free of anyprojections or obstructions other than the hollow fill stem.
 12. Theball of claim 11 with the ball weighing 375 to 475 grams.
 13. The ballof claim 11 with the particulate comprising 60 to 90% by weight of thefill material.
 14. The ball of claim 1, wherein no sealing material isdisposed on the plug.